US4652950A - Floppy disc driving apparatus - Google Patents

Floppy disc driving apparatus Download PDF

Info

Publication number
US4652950A
US4652950A US06/537,494 US53749483A US4652950A US 4652950 A US4652950 A US 4652950A US 53749483 A US53749483 A US 53749483A US 4652950 A US4652950 A US 4652950A
Authority
US
United States
Prior art keywords
index
floppy disc
head
signal
level
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/537,494
Other languages
English (en)
Inventor
Tetsuro Ichitani
Shunzi Saito
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tokyo Electron Ltd
Toshiba TEC Corp
Original Assignee
Tokyo Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tokyo Electric Co Ltd filed Critical Tokyo Electric Co Ltd
Assigned to TOKYO ELECTRIC CO., LTD., A CORP. OF JAPAN reassignment TOKYO ELECTRIC CO., LTD., A CORP. OF JAPAN ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ICHITANI, TETSURO, SAITO, SHUNZI
Application granted granted Critical
Publication of US4652950A publication Critical patent/US4652950A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02—Control of operating function, e.g. switching from recording to reproducing
    • G11B19/06—Control of operating function, e.g. switching from recording to reproducing by counting or timing of machine operations
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02—Control of operating function, e.g. switching from recording to reproducing
    • G11B19/12—Control of operating function, e.g. switching from recording to reproducing by sensing distinguishing features of or on records, e.g. diameter end mark
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B21/00—Head arrangements not specific to the method of recording or reproducing
    • G11B21/02—Driving or moving of heads
    • G11B21/12—Raising and lowering; Back-spacing or forward-spacing along track; Returning to starting position otherwise than during transducing operation

Definitions

  • This invention relates to a floppy disc driving apparatus.
  • An apparatus for driving a floppy disc used as external memory or the like includes a disc driving mechanism for rotating a floppy disc, a head load mechanism operable in response to a drive signal to set a head in contact with the floppy disc for writing or reading data and a head positioning mechanism for setting the head in a position of a selected track.
  • the head load mechanism operates to load upper and lower heads when a floppy disc is not set, the upper and lower heads strike to each other and may be damaged.
  • a detecting circuit for checking whether a floppy disc is set or not is heretofore used. If no floppy disc is set, it provides an inhibition signal to the head load mechanism to inhibit the driving of the head to the contact position. The use of such detecting circuit, however, complicates the structure and increases the size of the driving apparatus.
  • the floppy disc driving apparatus of this type includes an index sensor, which produces an index signal by detecting an index hole formed in the floppy disc for each rotation thereof. Successive output signals from the index sensor may be counted, and a permission signal to bring the head in contact with the floppy disc may be given to the head load mechanism when a predetermined count of output signals is reached. In this case, however, the head cannot be set in the contact position until the floppy disc has been rotated a predetermined number of rotations.
  • An object of the invention is to provide a floppy disc driving apparatus, which is simple in construction and can promptly drive the head to the operating position.
  • a floppy disc driving apparatus which comprises a disc drive circuit for rotating a floppy disc, a head load circuit for driving a head to a position in contact with the floppy disc, an index sensor for generating an index signal for each rotation of the floppy disc, a load signal generating circuit for generating a head load signal for driving the head to a contact position, and a control circuit for making the head load signal from the load signal generating circuit ineffective when detecting that the output signal from the index sensor is held at a predetermined level for a preset period of time longer than the time required for one rotation of the floppy disc.
  • the head load signal is rendered ineffective when it is detected that the output signal from the index sensor is held at a predetermined level for a preset period of time longer than the time required for one rotation of the floppy disc.
  • the head can be promptly driven to the contact position without incurring the possibility of damaging the head.
  • FIG. 1 is a schematic sectional view showing an essential portion of an embodiment of the floppy disc driving apparatus according to the invention
  • FIG. 2 is a perspective view showing a head load mechanism of the floppy disc driving apparatus shown in FIG. 1;
  • FIG. 3 is a circuit diagram showing the circuitry of the embodiment of the floppy disc driving apparatus according to the invention.
  • FIG. 4 is a block diagram showing a different embodiment of the floppy disc driving apparatus according to the invention.
  • FIGS. 5 through 8 are flow charts for explaining the operation of the floppy disc driving apparatus shown in FIG. 4.
  • FIG. 1 shows an essential portion of an embodiment of the floppy disc driving apparatus according to the invention.
  • the illustrated floppy disc driving apparatus includes a base plate 1, and a motor 2 disposed beneath the base plate 1 which has a shaft 2A penetrating substantially a central portion of the base plate 1.
  • a floppy disc holding member 3 for holding a floppy disc 4 is mounted on the free end of the motor shaft 2A.
  • a support member 5 is provided at one end of the base plate 1, and it supports one edge of a cover plate 6.
  • a floppy disc positioning member 7 is mounted on substantially a central portion of the cover plate 6.
  • the positioning member 7 When the cover plate 6 is closed, the positioning member 7 is engaged in a recess 3A formed in the top of the floppy disc holding member 3 through a central hole or opening of the floppy disc 4, whereby the floppy disc 4 is held in a set position.
  • a guide rod 8 is provided on top of the base plate 1 such that it extends above and parallel to the top surface of the base plate 1 between the floppy disc holding member 3 and support member 5.
  • a head load (i.e. head drive) mechanism 9 is slidably mounted on the guide rod 8 to drive the head into its operable position.
  • a light-emitting diode 10A and phototransistor 10B are disposed such that they face each other on the opposite sides of the floppy disc 4 so that they can detect an index hole 4A formed in the floppy disc 4. They form a photo-coupler serving as an index sensor 10.
  • FIG. 2 shows the head load or drive mechanism 9 in detail. It includes a head holder 91 pivoted at an end 92.
  • the head holder 91 has arms 93 projecting sidewise from its central portion.
  • a lever 95 has one end engaging one of the arms 93 and the other end coupled to a spring 94. It is swingably supported by a support 96 at its intermediate portion between the two ends.
  • the spring 94 serves to bias the other end of the lever 95 downwordly, that is, biases the one end of the lever 95 upwardly.
  • a solenoid 97 is coupled to the lever 95, and it serves to move the one end thereof downwards against the biasing force of the spring 94.
  • FIG. 3 shows the circuit of the embodiment of the floppy disc driving apparatus according to the invention.
  • the light-emitting diode 10A is connected in series with a resistor 15 between a power supply terminal VD and ground.
  • the phototransistor 10B is an npn transistor having the collector connected to the power supply terminal VD through a resistor 16 and the emitter grounded.
  • the collector of the transistor 10B is connected to an input terminal A of a re-triggerable one-shot multivibrator 17 through an inverter 18.
  • the one-shot multivibrator 17 generates from an output terminal Q an output pulse having a duration longer than the time required for one rotation of the floppy disc in response to the fall of the input signal to the input terminal A.
  • the output terminal Q of the one-shot multivibrator 17 is connected to one input terminal of two-input NAND gate 20.
  • the other input terminal of the AND gate 20 receives a head-load signal supplied from a head-load signal generating circuit 21.
  • the output terminal of the NAND gate 20 is connected to the base of a pnp transistor 22, which has its emitter connected to the power supply terminal VD through the solenoid 97 and its collector grounded.
  • the index sensor 10 supplies an output pulse through the inverter 18 to the one-shot multivibrator 17 each time the index hole 4A in the floppy disc 4 comes to a position in register with the index sensor 10.
  • the one-shot multivibrator 17 In response to the fall of the pulse from the inverter 18, the one-shot multivibrator 17 generates an output pulse having a predetermined duration.
  • the duration of this output pulse is set to be longer than the time required for one rotation of the floppy disc 4. Since the one-shot multivibrator 17 is retriggerable and is triggered by successive output pulses each generated from the index sensor 10 for each rotation of the floppy disc 4, it continuously generates from its output terminal Q an output signal at a high level, so that the NAND gate 20 is continuously kept enabled. In this state, the NAND gate 20 will provide a low level signal to turn on the transistor 22 when a head load signal for driving the head section 91 to bring the head into contact with the floppy disc 4 is generated from the head-load signal generating circuit 21.
  • the cover plate 6 is closed without any floppy disc 4 set on the floppy disc holding member 3.
  • the index sensor 10 produces no output pulse when the motor 2 is driven.
  • the one-shot multivibrator 17 thus continuously provides a low level output signal, so that the NAND gate 20 continuously provides a high level output signal irrespective of the output signal from the control signal generating circuit 21.
  • the transistor 22 is thus held “off”. That is, the solenoid 97 is never energized, and the one end of the lever 95 is held in the upwardly biased position by the spring 94 to hold the head section 91 in a retracted position.
  • FIG. 4 shows an electronic circuit section of a different embodiment of the floppy disc driving apparatus according to the invention.
  • This electronic circuit includes a CPU 100 and a ROM 102 and RAM 104 both coupled to the CPU 100 through a data bus.
  • An index sensor 106, a head driver 108, a head-load driver 110, a timer 112 and a host computer 114 are further coupled to the CPU 100 through I/O ports 116 to 119 and an interface circuit 120, respectively.
  • a write-in circuit 122 for supplying write-in data to a head HD, a read-out circuit 124 for reading data through the head HD and a motor driver MD for driving the motor 2 are coupled to the host computer 114.
  • the motor 2 is rotated at a speed of, for instance, one rotation per 200 msec.
  • the index sensor 106 When the motor 2 is driving the floppy disc at the constant speed, the index sensor 106 generates a 6-msec high level signal each time it detects the index hole.
  • the CPU 100 sets the timer 112 to 220 msec., for instance, each time it detects the rising of an output signal from the index sensor 106.
  • the timer 112 supplies an interruption pulse to the CPU 100.
  • the CPU 100 sets a head-load flag HFL to "0".
  • the RAM 104 includes an index flag IFL as well as the head-load flag HFL.
  • the CPU 100 sets the index flag IFL and head-load flag HFL to "0" in an initialization step, and then it repeatedly executes index check, step check, index check and head-load check subroutines as shown in FIG. 5.
  • the CPU 100 first executes a STEP 1 to check whether the index signal from the index sensor 106 is at a high level. If the index signal is at the high level, i.e., when the phototransistor 10B shown in FIG. 3 is "OFF", the CPU 100 executes a STEP 2 to check whether the content of the index flag area in the RAM 104 is "1".
  • the processing returns to the main routine. If it is detected in the STEP 2 that the index flag IFL is "0”, the index flag IFL and head-load flag HFL are set to "1", and then the timer 112 is set to 220 msec. The processing is then returned to the main routine.
  • the CPU 100 executes a STEP 3 to check whether the index flag IFL is "1". If an answer "NO” is obtained in the STEP 3, the processing is returned to the main routine. If the answer is "YES”, the index flag IFL is set to "0", and then the processing is returned to the main routine.
  • both the index flag IFL and head-load flag HFL are set to "1", and then the timer 112 is set to 220 msec. and starts time-counting.
  • the timer 112 is set to 220 msec. again and starts the 220-msec. counting operation afresh. If it is not detected that the index signal becomes high before the completion of the 220-msec. counting operation, the timer 112 generates an interruption pulse, in response to which the CPU 100 sets the head-load flag HFL to "0".
  • the CPU 100 executes the step check subroutine as shown in detail in FIG. 7.
  • the CPU 100 first executes a check as to whether a track change signal is generated from the host computer 114. If this track change signal is detected, it supplies a drive signal to the head driver 108 according to head position designating data supplied from the host computer 114, thus setting the head to the designated track position. The processing is then returned to the main routine. If the CPU 100 detects no track change signal from the host computer 114, it returns the processing to the main routine. Subsequently, the index check subroutine as described before in connection with FIG. 6 is executed.
  • the CPU 100 executes the head-load check subroutine as shown in detail in FIG. 8.
  • the CPU 100 first executes a STEP 114 to check whether a head-load signal is generated from the host computer 114. If it detects the head-load signal, the CPU 100 executes a STEP 5 to check whether the headload flag HFL is "1". If the head-load flag HFL is "1", the CPU 100 supplies a drive signal to the head-load driver 110 to set the head in contact with the floppy disc 4. Subsequently, the index check subroutine as shown in FIG. 6 is executed. If the answer in the STEP 4 or 5 is "NO", the CPU 100 supplies a drive signal to the head-load driver 110 to set the head in a retracted position.
  • the content of the timer 112 never becomes “0”, and hence no interruption signal is supplied from the timer 112 to the CPU 100, so long as the floppy disc is rotated at a constant speed so that index hole is detected periodically.
  • the head-load flag HFL is "1" at all time, and the CPU 100 can drive the head into contact with the floppy disc when the head-load signal is supplied from the host computer 114.
  • the index sensor 106 continuously provides a low level index signal, so that the STEPs 1 and 2 yield the respective answers "NO".

Landscapes

  • Indexing, Searching, Synchronizing, And The Amount Of Synchronization Travel Of Record Carriers (AREA)
US06/537,494 1983-10-07 1983-09-30 Floppy disc driving apparatus Expired - Lifetime US4652950A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE3336528A DE3336528A1 (de) 1983-10-07 1983-10-07 Antriebsvorrichtung fuer eine floppy-scheibe

Publications (1)

Publication Number Publication Date
US4652950A true US4652950A (en) 1987-03-24

Family

ID=6211257

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/537,494 Expired - Lifetime US4652950A (en) 1983-10-07 1983-09-30 Floppy disc driving apparatus

Country Status (2)

Country Link
US (1) US4652950A (fr)
DE (1) DE3336528A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020027743A1 (en) * 2000-09-05 2002-03-07 Alps Electric Co., Ltd. Floppy disc driving device
US6513997B2 (en) 2000-07-17 2003-02-04 Toshiba Tec Kabushiki Kaisha Wire dot printer head and wire dot printer using the same
US6543944B2 (en) 2000-07-17 2003-04-08 Toshiba Tec Kabushiki Kaisha Wire dot printer head and wire dot printer using the same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5278718A (en) * 1991-05-24 1994-01-11 Samsung Electronics Co., Ltd. Circuit for generating a disk change signal

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3715523A (en) * 1970-07-02 1973-02-06 Honeywell Bull Soc Ind Positioning mechanism for magnetic head
US4375070A (en) * 1979-10-01 1983-02-22 Mitsubishi Denki Kabushiki Kaisha Magnetic head soft loading and unloading device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2283507A1 (fr) * 1974-07-30 1976-03-26 Staar Sa Dispositif d'arret automatique pour appareils d'enregistrement et/ou de reproduction
US4202020A (en) * 1978-08-31 1980-05-06 International Business Machines Corporation Magnetic head load control system
US4620249A (en) * 1981-04-28 1986-10-28 Ricoh Company, Ltd. Apparatus for driving a floppy disc

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3715523A (en) * 1970-07-02 1973-02-06 Honeywell Bull Soc Ind Positioning mechanism for magnetic head
US4375070A (en) * 1979-10-01 1983-02-22 Mitsubishi Denki Kabushiki Kaisha Magnetic head soft loading and unloading device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6513997B2 (en) 2000-07-17 2003-02-04 Toshiba Tec Kabushiki Kaisha Wire dot printer head and wire dot printer using the same
US6543944B2 (en) 2000-07-17 2003-04-08 Toshiba Tec Kabushiki Kaisha Wire dot printer head and wire dot printer using the same
US20020027743A1 (en) * 2000-09-05 2002-03-07 Alps Electric Co., Ltd. Floppy disc driving device
US6775095B2 (en) * 2000-09-05 2004-08-10 Alps Electric Co., Ltd. Floppy disc driving device

Also Published As

Publication number Publication date
DE3336528A1 (de) 1985-05-02
DE3336528C2 (fr) 1988-09-01

Similar Documents

Publication Publication Date Title
US4652950A (en) Floppy disc driving apparatus
US4644426A (en) Floppy disk drive apparatus
US4470675A (en) Random access control apparatus and method for slide projector
JPH0731410Y2 (ja) ディスク装置
US4870514A (en) Disk drive circuit arrangement for the suppression of undesired index pulses
JPS59176946U (ja) サンプリングノズルの衝突防止機構
JPS6355153B2 (fr)
CN100366437C (zh) 记录装置、记录头位置调整装置及记录头位置调整方法
JPH0565951B2 (fr)
GB1013841A (en) Reliability checking system for data sensing
US4745275A (en) Sensor circuit
US4947050A (en) Sensor bracket for magnetic tape cartridge drive
JPS5853429B2 (ja) 磁気デイスクの保護装置
JP4285798B2 (ja) 半導体装置
US4843406A (en) Method and apparatus for detecting the presence or absence of a pen in pen recorder
JPH0313667B2 (fr)
KR910000317Y1 (ko) 플로피디스크의 안착장치
KR860002465Y1 (ko) 플로피 디스크의 오삽입 방지 장치
KR920001956B1 (ko) 플로피디스크 제어회로
JPS6213744B2 (fr)
JPS6029971A (ja) デイスク駆動装置
JPS61129553A (ja) サンプルピツトの位置決め方法とその装置
JPH04221401A (ja) 磁気ディスク装置
JPS60164960A (ja) フロツピーデイスク駆動装置
GB1425125A (en) Apparatus for reading a record member

Legal Events

Date Code Title Description
AS Assignment

Owner name: TOKYO ELECTRIC CO., LTD., 6-13, 2-CHOME, NAKAMEGUR

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:ICHITANI, TETSURO;SAITO, SHUNZI;REEL/FRAME:004181/0693

Effective date: 19830920

STCF Information on status: patent grant

Free format text: PATENTED CASE

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 12